Ice Damming Causes and Solutions


Historically ice dams in Oklahoma have not been a problem.  However, over the last several years the weather patterns in Oklahoma have made many of us all too familiar with ice dams.  Below you will find information that will offer some insight to the ice dams, what causes them, how to prevent them and how to deal with them when they already exist. 

Three things are required for an ice dam to form: snow, heat to melt the snow and cold to refreeze the melted snow into solid ice. Ice dams develop as snow on the upper part of the roof melts.  Heat from the building’s interior rises to cause the melt, poorly insulated building are most prone to this problem.

 Water runs down the roof slope under the blanket of snow and refreezes into a band of ice at the roof’s edge creating a “dam”. Additional snow-melt pools against the dam and eventually leaks into the building through the roof or roof trim. The worst ice dams usually occur when a deep snow is followed by very cold weather, like we are presently seeing.

Keep in mind that steep slope roof applications are not waterproof.  They are comprised of overlapping shingles designed to shed water. When ice and water go backward or up the slope of the roof, because of pooling, these steep slope applications can leak.

Once snow and ice build up on the roof it is difficult to remove. There are several potential solutions that are discussed, each of which comes with its own set of unique risks. We will discuss the solutions and their risk below. 

ØThe Hammer:Some people have reported climbing a ladder and beating the ice and snow off the eve of the house with a hammer, 2X4 or other device to break it up and remove it. The Risk: ladders and snow do not mix see bullet one.  Any time you strike a roof with any device there is a real risk of damaging the roof surface.

ØHot Water Treatment: A person can hook a hose up to the hot water heater in their home and spray hot water on the roof to melt the snow and ice. The Risk: the distance from the water heater to the roof will probably require more than one hose.  Anyone who waters in the summer knows that hoses tend to leak, especially at the joints.  This could result in scalding hot water causing interior damage to your floors and wood work.  There is also a risk of being burned when dealing with hot water in a hose. 

ØThe Snow Rake:many people suggest fashioning a long handled rake to remove the bulk of the snow from the roof. Without the heavy blanket of snow many roof surfaces will heat up enough under sunlight to melt the remaining ice.  The Risk: If using a snow rake form the ground (recommended) the homeowner still faces the hazards of sub-freezing temperatures, slip and fall risk from ice on the ground and the risk of the ice and snow suddenly breaking free from the roof and crashing into them.  Keep in mind that when using a roof rake you are bringing ice and snow toward your body with nothing to stop it from hitting you.  This method also tends to damage the roof by removing the protective granules from the surface of the shingles and or breaking the shingles as they are brittle in cold temperatures. 

ØThe Melt Sock:  This method involves placing ice melt (calcium chloride) in a thin sock or panty hose and placing it on the base of the dam thus freeing up an area for water to drain from the structure.  The Risk:  Placing anything on your roof always presents some hazards but in conditions where ice damming exists those hazards are magnified. A person is exposed to brutally cold temperatures for a period of time.  In order to reach the roof a ladder must be erected and placed against the roof.  Normally this is not an issue but when you add ice and snow on the ground, the roof, your boots and the ladder the process becomes quite risky.

A brief safety note on commercial buildings during icy weather: Many commercial structures have metal roof systems, especially to create overhangs.   This kind of roof heats up quickly in direct sunlight and will often shed large amounts of ice and snow at once because there is no aggregate or friction on the roof surface.  A good tip is to park your car back from the roof line of these buildings and take extra care when walking near them.

In summary there is no simple solution for ice dams once they occur.  Our advice is to manage the leak immediately and complete repairs and take preventative measures after the snow has melted; assess your ventilation, insulation and “hot spots” in the roof.  Material that fully seals the roof can be added to prevent leaking caused by ice dams in leak prone areas.

If you find a leak in your house drive a small nail through the drywall in the center of the leak and attach a string from the nail into a bucket.  This will minimize damage to drywall and flooring making the repair smaller and less costly.

Please call a local contractor to help you deal with existing ice dams and create a prevention plan for the future.  It is extremely dangerous to climb on your roof when it is covered with ice and snow.  Snow removal from a roof surface can be tricky and if done improperly it can cause damage to the roof surface. 

Published with permission from:

Clint Rayburn

Marketing Manager

Red River Roofing & Construction Inc.